NEWS
the 45th Workshop on Photochemistry for Young Researchers_Chair and Awarded
6月14日~16日に伊豆山研修センターで行われた第45回光化学若手の会に参加しました。
今回、関が世話人となって明治薬科大学の木村先生と京都大学の山内先生とともに、準備をしました。
関研からはM2の岡田君と斎藤君、M1の石川君と矢野君の4人が参加しました。
2日目にポスター発表を行い、矢野君が優秀ポスター発表賞を受賞しました（博士学生の受賞が多く、修士の受賞は他に1人のみ）。
準備や当日の運営など、大変でしたが無事に終われてよかったです。
学生のみんなは、炎天下の中、タクシー移動の誘導の大役をこなしてくれました。
全ての参加者にあらためて感謝いたします。
Welcome party
Welcome party for new B3 students of Department of Chemistry at the cafeteria.
All the professors and B4/M1/M2 students were also joined.
BBQ w/ Kobayashi sensei, Tsukada Sensei, and their students
BBQ with Kobayashi and Tsukada groups.
Nice opportunity to spend time with students and professors.
RESEARCH
Our group develops stimuli-responsive molecular-based materials, such as crystals, liquid crystals, organogels and etc. We try to elucidate so far unknown responses of such materials and provide novel functionality of molecules.
Molecular-based materials exhibiting stimuli-responsivity
Molecular crystals or liquid crystals often show properties and functionality different from its individual molecule itself. This is caused by the neighboring molecules within the assembled materials which are connected through various intermolecular interactions. This indicates that the molecular-based materials can show properties/functionalities based on assembled states. Upon applying external stimulations to such materials, such as temperature change, photoirradiation and mechanical stimulations, the assembled states/molecular arrangements can change. As a result, these molecular-based materials exhibit various responses, i.e., property changes and mechanical movement.
Bridging the gap between macroscopic externals stimulation and microscopic molecular arrangement
We have reported that the molecular-based materials exhibiting emission color changes, electronic conductivity changes, and mechanical movements upon applying mechanical stimulation. These stimuli-responses are caused by the “macroscopic” mechanical force by means of a spatula or a pestle/mortar, which leading to changes in “macroscopic” molecular arrangements and patterns of intermolecular interactions. Our group tries to elucidate precise molecular arrangements within the crystals/liquid crystals to identify the effect of external stimulation, bridging the gap between macro- and microscopic information.
Publications
2024
T. Seki, S. Kobayashi, R. Ishikawa, K. Yano, T. Matsuo, S. Hayashi,
Chem. Sci., 2024, in press
DOI: 10.1039/d4sc02918f.
T. Seki, K. Hattori,
RSC Adv., 2024, 14, 11, 7258–7262
DOI: 10.1039/d3ra08519h.
2023
T. Seki, D. Korenaga,
Chem. Eur. J., 2023, 29, 62, e202302333
DOI: 10.1002/chem.202302333.
2022
C. Feng, T. Seki, S. Sakamoto, T. Sasaki, S. Takamizawa, H. Ito,
Chem. Sci., 2022, 13, 9544–9551
DOI: 10.1039/D2SC03414J.
Shape-memory materials can be mechanically deformed and subsequently reverse the deformation upon changing the temperature. Shape-memory materials have attracted considerable attention for basic research and industrial applications, and polymer and alloy shape-memory materials have been well studied; however, it is formidably challenging to develop functional shape-memory materials, such as materials with multi-stage and anisotropic shape changes and shape changes accompanied by changes in color and light emission. Here, we found a reversible multi-stage shape-changing effect after mechanical deformation in a molecular crystal induced by multi-step thermal phase transitions with reversible shape changes and luminescence-color changes. Using single-crystal structure and thermal analyses as well as mechanical property measurements, we found that the reversible multi-stage shape-changing effect was achieved by a combination of a twinning deformation and multi-step thermal phase transitions. The changes in the crystal shape and luminescence suggest novel strategies for imparting known shape-memory materials with additional functionalities.